James Blake was first reinstated and then told he had not gone through in Las Vegas

The format was severely criticised by some of tennis's top players, including world number one Roger Federer.

The system also ran into trouble at the Las Vegas Open when there was confusion over who should qualify when a player withdrew injured from a match.

"Remaining events who had volunteered for the round-robin format will revert to knock-out," an ATP statement said.

"The ATP had begun testing several versions of the format at lower level events this year following initial research that indicated it could be a measure to provide significant growth to the game.

I don't regret, and I never regret, trying things that make this sport better and bigger Etienne de Villiers, ATP chief executive

"The research showed it was popular among casual fans.

"However, the carefully monitored testing at the five test case events this year raised a number of concerns and weaknesses that were not apparent from desk research.

"Firstly, the 32 hybrid format caused confusion; second, resolving who would progress from the round robin stage with three-men groups was often complicated; and third, sections of the media had difficulty in reporting round-robin and consequently fans not at the event had difficultly in following early results.

"Finally, and significantly, no format or rule could address the overwhelming player concern that their destiny was not in their own hands as a result of dead matches or withdrawals."

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ATP chief executive Etienne de Villiers, who earlier this month apologised after personally intervening in the Las Vegas situation, insisted he would not shy away from further experimentation.

"I regret that I got involved, I made a mistake," he told Five Live. "Hopefully, by owning up quickly it didn't affect anyone's life or anyone's livelihood.

"But I don't regret, and I never regret, trying things that make this sport better and bigger.

"We will continue to experiment. What we tried was the extension of a system that has been used many, many times to see whether it would actually do some good for our sport.